Prognostic Factors in Oligodendrogliomas: a Clinical Study of Twenty-Five Consecutive Patients

Atalay, Tugay,Ak, Hakan,Celik, Bahattin,Gulsen, Ismail,Seckin, Hakan,Tanik, Nermin,Albayrak, Sedat Baki,Bavbek, Murad Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.13

Background: The purpose of this study was to evaluate the prognostic significance of Ki-67 and subjective microvascular density (SMVD) indexes together with other factors in patients with oligodendroglioma. Materials and Methods: In this retrospective study, oligodendroglioma specimens obtained from twenty-five consecutive patients were evaluated for Ki-67 and SMVD indices to help determine histological grading and investigate the fidelity of these markers in clinical prognosis. Other potentially prognostic factors were Karnofsky performance scale, tumor histological grade, and adjuvant radiotherapy. Results: The Ki-67 proliferation index appeared to have a strong correlation with the grade of the tumor and the survival. Age, gender, adjuvant radiotherapy, surgical resection type (complete versus incomplete) did not have any influence on recurrence. The SMVD index correlated significantly with the 3 to 5-year survival. Conclusions: Ki-67 and MVD indexes are important and useful markers in estimating the prognosis of oligodendrogliomas.

Diagnostic Utility of Osteocalcin, Undercarboxylated Osteocalcin, and Alkaline Phosphatase for Osteoporosis in Premenopausal and Postmenopausal Women

Sacide Atalay,Abdullah Elci,Huseyin Kayadibi,Can B Onder,Nurettin Aka 대한진단검사의학회 2012 Annals of Laboratory Medicine Vol.32 No.1

Background: We aimed to investigate the diagnostic utility of osteocalcin (OC), undercarboxylated osteocalcin (ucOC), and alkaline phosphatase (ALP) in pre- and postmenopausal women for femoral neck, L1-4, and L2-4 bone mineral density (BMD) values by taking into consideration their age, body mass index (BMI), and menopausal status. Methods: Premenopausal (N=40) and postmenopausal cases (N=42) were classified as 25-34 or 35-45 yr of age and within the first 5 yr or 5 yr or more after the onset of menopause, respectively. Results: Among the groups, statistical differences were found for age, BMI, OC, ucOC, ALP, femoral neck BMD, L1-4 BMD, and L2-4 BMD. The highest serum OC, ucOC, and ALP levels were observed in cases within the first 5 yr after the onset of menopause, probably due to a more rapid bone turnover rate. The best predictors for the femoral neck osteoporosis were ALP, OC, and calcium (areas under the ROC curve [AUC]=0.882, 0.829, and 0.761, respectively), and those for L1-4 and L2-4 osteoporosis were OC, ALP, and ucOC (AUC=0.949, 0.873, and 0.845; and 0.866, 0.819, and 0.814, respectively). Multiple logistic regression analysis revealed that the most discriminative parameter for osteoporosis was OC. Conclusions: These results indicate that serum OC levels, with or without ucOC and ALP, may be useful to monitor follow-up changes that currently cannot be assessed with BMD and to diagnose femoral neck, L1-4 spine, and L2-4 spine osteoporosis. Background: We aimed to investigate the diagnostic utility of osteocalcin (OC), undercarboxylated osteocalcin (ucOC), and alkaline phosphatase (ALP) in pre- and postmenopausal women for femoral neck, L1-4, and L2-4 bone mineral density (BMD) values by taking into consideration their age, body mass index (BMI), and menopausal status. Methods: Premenopausal (N=40) and postmenopausal cases (N=42) were classified as 25-34 or 35-45 yr of age and within the first 5 yr or 5 yr or more after the onset of menopause, respectively. Results: Among the groups, statistical differences were found for age, BMI, OC, ucOC, ALP, femoral neck BMD, L1-4 BMD, and L2-4 BMD. The highest serum OC, ucOC, and ALP levels were observed in cases within the first 5 yr after the onset of menopause, probably due to a more rapid bone turnover rate. The best predictors for the femoral neck osteoporosis were ALP, OC, and calcium (areas under the ROC curve [AUC]=0.882, 0.829, and 0.761, respectively), and those for L1-4 and L2-4 osteoporosis were OC, ALP, and ucOC (AUC=0.949, 0.873, and 0.845; and 0.866, 0.819, and 0.814, respectively). Multiple logistic regression analysis revealed that the most discriminative parameter for osteoporosis was OC. Conclusions: These results indicate that serum OC levels, with or without ucOC and ALP, may be useful to monitor follow-up changes that currently cannot be assessed with BMD and to diagnose femoral neck, L1-4 spine, and L2-4 spine osteoporosis.

Evaluation of Energy Efficiency of Thermoelectric Generator with Two-Phase Thermo-Syphon Heat Pipes and Nano-Particle Fluids

Tahsin Atalay,Yavuz Köysal,Ali Ekber Özdemir,Engin Özbaş 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.5 No.1

This paper investigates the effects of heat pipes filled with water and nanoparticles (MgO) on electricity generation. The experimental setup comprises of two-phase thermo-syphon heat pipes filled with water or MgO nanoparticle-water suspension, thermoelectric generator (TEG) modules and heat sinks that use passive and active cooling systems. Concentrated solar radiation with heat pipes was used as a heat source for heating. Specially constructed heat sinks with coolant tunnels were used for cooling. Heating and cooling processes are needed to create a temperature difference to generate electrical energy. The constructed model represents the influence of basic parameters such as the tilt angle of heat pipes, working fluids, cooling process, etc. on the maximum power generated. Systems in the constructed setup were arranged with a specific angle to the incident angle of solar radiation. The experiment was carried out on August 5th, 2015, in the northern coast of Turkey, city of Samsun with latitude of 41o14’ N. The results obtained show that the presented experimental setup can be used to evaluate thermoelectric energy potential of local areas or to investigate optimum cooling or heating processes.

The effects of flavanoid on the treatment of hepatopulmonary syndrome

Talha Atalay,Murat Cakir,Ahmet Tekin,Tevfik Kucukkartallar,Suleyman Kargin,Adil Kartal,Adnan Kaynak 대한외과학회 2013 Annals of Surgical Treatment and Research(ASRT) Vol.85 No.5

Purpose: Hepatopulmonary syndrome is an arterial oxygenation disorder brought about by advanced liver failure and pulmonary vascular dilatations. The reason why hypoxia develops in hepatopulmonary syndrome depends on the broadening of perialveolar capillary veins. Our study aims to investigate the effects of Flavanoid on hepatopulmonary syndrome through its inhibition of nitric oxide. Methods: Three groups, each having 8 rats, were formed within the scope of our study. Group I (the control group) only received laparatomy, group II received choledoch ligation, and group III was administered Flavanoid (90% flavonoid diosmin, 10% flavonoid hesperidin) following choledoch ligation. The rats were administered Flavanoid at week two following choledoch ligation. The rats’ livers and lungs were examined histopathologically following a five-week follow-up and the perialveolar vein diameters were measured. Arterial blood gases and biochemical parameters were evaluated. Results: It was seen that fibrosis and oxidative damage in the liver with obstructive jaundice as well as hypoxia with pulmonary perialveolar vein sizes were significantly lower than the other group with cirrhosis formed through the administration of Flavanoid. Conclusion: We have concluded that Flavanoid administration might be useful in the treatment of hypoxia in hepatopulmonary syndrome and the delay of cirrhosis contraction.

Experimental and Thermal Analysis of Solar Thermoelectric System Performance Incorporated with Solar Tracker

Tahsin Atalay,Yusuf Yakut,Yavuz Köysal,Seyda Özbektaş,Hakan Bülbül,Bahattin Topaloğlu 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.2

In this study, it is aimed to determine the energy generation capability of the designed and manufactured thermoelectric system when mounted on the two-axis solar tracking system. Thus, it was possible to compare the results obtained from current study with previous study. The system used in previous study was comprised of a thermoelectric generator (TEG) for energy conversion, a linear Fresnel lens for concentrating solar rays, and a one-axis tracking system to increase the electrical and thermal efficiency of the system. In this study, a dual-axis (two-axis) tracking system was used as a tracking system to examine the change in thermal and electrical efficiency. Therefore, experimental measurements were performed again using both two-axis and one-axis solar tracking systems on 16th October 2019 and 17th October 2019, respectively, at the location which falls at 41°14′ N and 36°26′ E. Additionally, the heat transfer and electricity generation performance of TEG was theoretically analyzed using CFD model. For this purpose, a numerical model consisting TEG with heat sink was developed. It was observed that the model data obtained and the experimental data were in good agreement. The values of parameters such as temperature, solar radiation, wind speed and TEG open circuit voltage were measured instantaneously during the measurements. The maximum open circuit voltages obtained is 1.02 and 1.13 V for one-axis and dual-axis systems, respectively. The solar radiation values were measured as 464 and 472 W∕m2 , respectively when the maximum open circuit voltages value is obtained. The duration for measurements was kept about 15 min so that the average values of these parameters were used in calculations. Thus, the values of maximum output power ( P maxout) , electrical efficiency (ηe) and Seebeck coefficient ( TEG) were calculated and given in the paper.

Detection of progressive and regressive phase and LINE-1 retrotransposon in transfected dogs with transmissible venereal tumor during chemotherapy

Sevil Atalay Vural,Rifki Haziroglu,Mehmet R. Vural,Ibrahim M. Polat,Arda S. Tunc 대한수의학회 2018 Journal of Veterinary Science Vol.19 No.5

Canine transmissible venereal tumor (CTVT) is a tumor that commonly occurs in genital and extragenital sites of both genders. Long interspersed nuclear elements (LINE-1) retrotransposon has a pivotal role in allogenic transfection among uncontrolled dog populations. This study aimed to perform pathomorphological, immunohistochemical, and in situ polymerase chain reaction (PCR) evaluation of CTVT (n = 18) in transfected dogs during chemotherapy. Immunohistochemically, tumor phases were investigated by using specific markers (CD3, CD4, CD8, CD79, and transforming growth factor beta [TGF-b]), and investigated an amplified specific sequence of TVT LINE-1 retrotransposon by in situ PCR. Polyhedral-shaped neoplastic cells that had large, round, hypo/hyperchromatic nuclei and eosinophilic cytoplasm were detected. All marker results were positive, especially in the early weeks of recovery. CD4 and TGF-b markers were conspicuously positive at the initial stage. In situ PCR LINE-1 sequence was initially positive in only four cases. It is believed that the CD and TGF-b markers provide phase identification at tumor initiation and during chemotherapy. It is thought that presence of T and B lymphocytes, which have roles in cellular and humoral immunity, is needed so that regression of the tumor is possible.

The Use of Pistachio Pollen for the Production of Nanostructured Porous Nickel Oxide

F. E. Atalay,E. Yigit,Z. S. Biber,H. Kaya 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.12

Natural biotemplates — such as bacteria, fungi and viruses — are used in nanostructured metal oxide production. The pollen can be found abundantly in nature, and their microcapsules can be easily isolated from the pollen by chemical treatments. To date, pollen microcapsules are mostly used as drug carriers and catalytic agent templates. In the present study, nanoporous-structured nickel oxide is produced using Pistachio pollen microcapsules. The raw pollen, chemically treated pollen and metal-coated pollen were characterized using scanning electron microscopy, Brunauer–Emmett–Teller (BET) surface area analysis, thermogravimetric analysis (TGA), differential thermal analysis (DTA) and X-ray diffraction (XRD) techniques. The natural Pistachio pollen which were procured from Gaziantep, Turkey, are spherical, with a diameter of approximately 23 μm. The maximum surface area obtained for nickel oxide-coated microcapsules is 228.82m2/g. This result shows that Pistachio pollen are an excellent candidate for the production of porous nanostructured materials for supercapacitor electrodes.

Are the functional movement analysis scores of handball players related to athletic parameters?

Emre Serdar Atalay,Devrim Tarakci,Candan Algun 한국운동재활학회 2018 JER Vol.14 No.6

Risk Factors of Lymph Node Metastases with Endometrial Carcinoma

Cetinkaya, Kadir,Atalay, Funda,Bacinoglu, Ahmet Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

Background: The purpose of this study was to investigate and evaluate risk factors for lymph node metastases (LNM) in cases of endometrial cancer (EC). Materials and Methods: A retrospective single institution analysis of patients surgically staged for EC at Ankara Oncology Education and Research Hospital from 1996 to 2010 was performed. Roles of prognostic factors, such as age, histological type, grade, depth of myometrial invasion, cervical involvement, peritoneal cytology, and tumor size, in the prediction of LNM were evaluated. Fisher's exact test and logistic regression analysis were used to assess the effects of various factors on LNM. Results: LNM was observed in 22 out of 247 patients (8.9%) and was significantly more common in the presence of tumors of higher grade, deep myometrial invasion (DMI), cervical involvement, size >2cm, and with positive peritoneal cytology. Logistic regression analysis revealed that DMI remained the only independent risk factor for LNM. NPV, PPV, sensitivity, and specificity for satisfying LNM risk were 98.0, 19.5, 86.3, and 65.3%, respectively for DMI. Conclusions: The incidence of LNM is influenced independently by DMI. If data support a conclusion of DMI, LND should be seriously considered.

Comparative analysis of existing reinforced concrete buildings damaged at different levels during past earthquakes using rapid assessment methods

Sezer Aynur,Hilal Meydanli Atalay 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.85 No.6

Türkiye is located in a region where destructive earthquakes are frequently experienced due to its geological characteristics and geographical location. Therefore, considering the possibility of a devastating earthquake at any time, determining the reinforced concrete (RC) building seismic safety, constructed before or after the current seismic buildings code, is one of the most important issues to be completed firstly. For this purpose, rapid assessment methods developed to quickly determine the seismic safety of buildings are available in the literature. Comparison of the principles of Principles of the Determination of Risky Structures-2019, Column and Wall Index Method, P25 Scoring Method and Improved Discriminant Analysis Method, which are among these methods, have been aimed within the scope of this study. Within the scope of this paper, a total of 43 buildings in the Yalova/Çınarcık region of Türkiye that the damage level was determined by street observation method immediately after the 1999 Kocaeli (Izmit) Earthquake; 15 buildings with heavy damage and 28 buildings with moderate damage were examined by rapid assessment methods. Although the risk detection difference was not separated as a clear line in any of the methods used, the results obtained from the rapid assessment methods are evaluated as being compatible with the detected after earthquake structural seismic behavior of the buildings. The PDRS-2019 and column and wall index method gave the most approximate results. In the results obtained from the analyzes; structural features such as number of floors, frame continuity, soft/weak story irregularity, effective shear strength area, existence of heavy overhangs in plan, type of structural system have been found to be significantly effective on the earthquake behavior of buildings.